<h3>
  这里是段子列表
</h3>
<form class="form-horizontal">
  <div class="form-group">
    <div class="col-xs-12">
      <input type="text" class="form-control" placeholder="写一个段子吧！" [value]="jokeContent" (change)="writeJoke($event.target.value)" name="jokeContent">
    </div>
  </div>
  <div class="form-group">
    <div class="col-sm-10">
      <button type="button" class="btn btn-success" (click)="saveContent()">提交</button>
    </div>
  </div>
</form>